Entosphenus tridentatus
Entosphenus tridentatus (''Pacific lamprey)' Kingdom: '''Animalia Phylum: Chordata Class: Cephalaspidomorphi Order: Petromyzontiformes Family: Petromyzontidae Genus: Entosphenus Species: Entosphenus tridentatus Environment: milieu, climate zone, depth range, distribution range: Marine; freshwater; brackish; demersal; anadromous; depth range 0 - 1508 m. Temperate; 65°N - 32°N, 133°E - 114°W. Distribution: North Pacific: Bering Sea coasts of Asia and Alaska southward to the Yuhutu River, Hokkaido, northern Japan and Punta Canoas, central Baja California, Mexico. The populations were, at one time, split into two groups as Entosphenus tridentatus tridentatus which ranged from the Columbia River to Alaska, and Entosphenus tridentatus ciliatus which ranged from Klamath River southwards. This division no longer holds. Freshwater resident populations exist in Culrus Lake and the Columbia River, British Columbia, the Sprague River in Oregon, the Goose Lake in Oregon/California, and the Klamath and Shasta rivers and Copco Lake in California. Size, weight, age: Max. length: 76 cm, common length: 41 cm; weight: 500 g; age: 9 years Short description: Pacific lampreys grow to about 80 cm (31 in) as adults. They are anadromous and semelparous. They have slender, elongated bodies with two dorsal fins arising far back on the body. The anal fins are rudimentary and the lower lobe of the caudal fin is larger than the upper lobe and both lobes are continuous with the dorsal fin and the anal fin. Adults living in the sea are a bluish-black or greenish colour above and pale below, but those in fresh water are brown. This species is distinguished by having three (or occasionally two) sharp teeth on the supraoral bar above the mouth and three sharp points on each lateral plate. Biology: Anadromous, but also a number of permanent freshwater resident populations (Cultus Lake, British Columbia; Sprague River, Klamath River Basin, Oregon). In marine waters, adults mostly inhabit the mesopelagic zone down to 800 m depth and have been documented as far as 117 km off the coast of Oregon. In fresh waters, ammocoetes and adults inhabit lakes, rivers, and creeks. Ammocoetes occur in soft sediments in shallow areas along stream banks; in silt, mud, and sand of shallow eddies and backwaters of streams. Spawning adults are found in gravel riffles and runs of clear coastal streams; feeding adults usually in the ocean, but landlocked populations occur. Stops feeding once upstream spawning migration is underway. Parasitic adults attach themselves to the side or undersurface of its prey, from which it draws blood and body fluids as food. Preys on fishes and sperm whales. Adults are found in the Strait of Georgia from December to mid-June. The duration of the feeding phase at sea has been estimated at 20-42 months. In British Columbia, return to fresh water begins as early as April and is completed by September. In the Columbia River, prior to the completion of the Grand Coulee Dam in 1941, spawning migrations of 800 km up to Kettle Falls, Washington occurred. In order to cross barriers such as falls, they use their suctorial disc to attach to the vertical surfaces and slowly make their way up. In British Columbia spawning is in June to the end of July, while in Oregon, it begins in May at water temperatures of 10-15 °C and continues through July. Fecundity, 98,300-238,400 eggs/female in Oregon populations from Clear, Trout, and Cow creeks, respectively, in the John Day, Molalla, and Umpqua river basins. Death of spawners follows 3-36 days after spawning. Eggs are eaten by two species of fish in the Umatilla River, Oregon. Rarely consumed as food; prepared fresh or smoked. Sometimes processed into meal. The Native American tribes of the mid-Columbia River Plateau have an ongoing tradition dating back hundreds of years of harvesting Pacific Lamprey. The adults are caught either by hand or dipnet in areas where they congregate prior to spawning. They are prepared for human consumption either by drying or roasting. Caloric values for Pacific Lamprey range from 5.9 to 6.3 kcal/g wet weight. Their oil is also extracted and used for medicinal purposes. Ammocoetes are used as bait for introduced Micropterus dolomieu in the John Day River, Oregon. In 1812, Americans of European descent obtained Pacific Lamprey from the Umatilla tribe of Oregon for the purposes of consumption. In the early 1900s, fur trappers utilized Pacific Lamprey as bait for coyotes. A fishery for adult lamprey has existed at Willamette Falls on the Willamette River, Oregon at least since 1913. That year, 24.5 metric tons were harvested and ground into fishmeal for young hatchery salmon. Between 1943 and 1949, 740 metric tons in total were harvested and used for vitamin oil, food for livestock, poultry, and fishmeal. In 1994, about 1.8 metric tons were exported to Europe for human consumption. The North Carolina Biological Supply House regularly collects adults from this locality for use as teaching material. The effects of Pacific lamprey attacks on commercial species needs further studies. Life cycle and mating behavior: In the spring following the migration into fresh water, a male and a female dig a nest. In the spawning act, the female attaches herself to a rock and the male fastens its sucker on the head of the female and coils around the female. The two then vibrate and eggs and sperms are released. Males spawn with more than one female in different nests. Adults die 1-14 days after spawning, while other sources say adults die 3-36 days after spawning. Larvae remain buried in the stream bottom for up to 5 or 6 years and return to the sea after changing into the adult form. The parasitic adults spend 12-20 months in the sea before moving upstream to spawn. Main reference: Page, L.M. and B.M. Burr, 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p. IUCN Red List Status: Not Evaluated CITES: Not Evaluated CMS: Not Evaluated Threat to humans: Harmless Human uses: Fisheries: subsistence fisheries; bait: occasionally. Category:Petromyzontidae, Northern lampreys